Heavy oil and sand pump



3 Sheets-Sheet 1 C. J. COBERLY HEAVY OIL AND SAND PUIP III June 2l, 1949.

Filed lay 1:5. 1946 3 Sheets-Sheet 2 C. J. COBERLY HEAVY OIL AND SAND PUK? June 21, 1949.

Filed nay 1s, 1946 June 21 c, J. OBERLY HEAVY OIL AND SAND PUMP 3 Sheets-Sheet 3 Filed nay 13' 1946 ruw, 5 .LAR @QA ,N Wm mim Rn .A A./ K fi Patented June 21, 1949 2,4'ia,s64

HEAVY onJ AND SAND PUMP Clarence J. Coberly, Los Angeles, Calif., assigner to Kobe, Inc., Huntington Park. Calif., a corporation of California' Application May 13, 1946, Serial No. 669,410

This invention relates to hydraulic pumps and, more particularly, to a fluid-operated pump of the displacement type adapted to pump oil from a well.

Conventional duid-operated pumps of the displacement type, such as illustrated in my Patent No. 2,311,157, issued February 16, 1943, include a motor cylinder having a motor piston therein, a pump cylinder having a pump piston therein and connected by a piston rod with a motor piston, and master valve mechanism for alternatively directing high-pressure operating fluid, such as oil, to opposite ends of the motor cylinder to reciprocate the piston assembly to pump well fluid from the pump cylinder. In such devices the pistons have a substantially fixed stroke length, and reversal of direction of the pump piston cannot take place unless and until it completes its stroke.

Many oil wells produce oil having a high percentage of solids, such as, for example, sand, therein, and when such a conventional type of fluid-operated pump is utilized in pumping such a well it is commonly found that solids, such as sand, in the oil tend to collect in the pump cylinder. When this occurs the conventional pump piston may squeeze the oil through the sand in the pump cylinder, leaving a solid core of sand which stops the travel of the pump piston before it completes its stroke and prevents completion of the stroke. Since such pumps are of the constant displacement type, when the pump piston is prevented from completing its stroke the motor piston likewise stops, and the pump must normally be removed from the well to permit the accumulated sand to be removed from the pump. This requires an expensive pulling job, and complete disassembly of the pump for cleaning, and the well normally lies idle during such an operation, all of which is very undesirable.

It is therefore a primary object of this invention to provide a pump oi the fluid-operated type in which the pump piston will reverse its stroke when it contacts a mass of sand or other solid material in the pump cylinder. This prevents stoppage of the pump and permits uninterrupted production from the well, even though perhaps at somewhat reduced capacity.

Another object of this invention is to provide a {duid-operated pump of the character just described, in which means is provided therein for removing, or assisting in the removal of, sand or other solids from the pump cylinder during operation of the pump. I prefer to accomplish this by providing means for jetting a uid, such as oil, into the pump cylinder or chamber when the 26 claims. (cl. 1oz-4s) 2 pump piston contacts solid matter therein, so as to stir up and dislodge such sand so that it may be forced through the pump by the pump piston, and this is still another object of the invention.

A further object of the invention is to provide such a pump which is of the single-acting type, but in which high pressure operating fluid is employed to perform both strokes of the pump piston. I also prefer to provide such a pump in which the downstroke, or return stroke, is at relatively high velocity and in which the upstroke, or working stroke, is at relatively low velocity, so that the suction stroke utilizes about to of the total time of the pump cycle, which is particularly desirable where such a pump is employed to pump heavyv oil, and this is another object of the invention. Such a construction has the added advantage that a high-velocity downstroke oi the pump piston causes a rapid discharge of oil thereby which causes considerable turbulence tending to keep sand or other solid matter in suspension in the oil so that it can be discharged from the pump with the oil, and this is a further object of the invention. The low f velocity of the pump piston on its Working or intake stroke also has the added advantage that it does notreduce the intake pressure substantially below the duid pressure in the well, which is important because if the intake or working stroke is rapid the pressure in the inlet end of the pump cylinder may be reduced to a value at which gas in solution in the oil dashes out thereof to form a froth of free gas in the pump cylinder which greatly reduces the volumetric emciency l of the pump.

Still another object of the invention is to provide such a pump in which high pressure operating fluid at all times bears on a relatively small cross-sectional force area tending to move the pump piston downwardly, and in which such highpressure uid is intermittently admitted to a relatively large cross-sectional force area tending to move the pump piston upwardly.

Another object of the invention is to provide a pump as last described above in which such high-pressure operating iluid is admitted to a force area causing the pump piston to move upwardly when the pump piston strikes solid matter in the pump cylinder, regardless at what point this may occur on the downstroke of the pump piston. I prefer to accomplish this by employing such operating iiuid to perform the jetting action described above, and to use such Jetted iiuid to eiiect upward movement of the pump piston.

Yet a further object of my invention is to provide a fluid-operated pump having a pump piston equipped with a valve mechanism which, when the pump piston strikes solid matter in the pump cylinder, opens the valve to admit highpressure operating fluid to the bottom of the pump piston, tending to raise the pump piston.

Another object of the invention is to provide such a pump which will operate effectively to handle oil or other fluid containing sand or other solid matter. I accomplish this, in part, by the use of pump intake and discharge valves which are large relative to the pump diameter, which also facilitates the pumping of heavy or viscous crude oil, and is a separate object of the invention.

A further object of my present invention is 'to provide a fluid-operated pump having a unitary motor piston and'mainv valve, which simplifies -the construction and reduces the cost of manufacture.

Still another object of the invention is to provide a fluid-operated pump in which the operating fluid is supplied through a central tubular member on which the motor piston reciprocates, so that the motor and pump cylinders can be simple tubular members. This feature has the added advantage that the fluid pressure of the operating fluid is at all times directed radially outwardly in the motor and pump cylinders.

Another object of the invention is to provide a pumping m'ethod for sandy oil wells in which the potential energy of the downwardly moving column of operating' fluid is converted and released as kinetic energy to flush out sand collected in the pump chamber, and to use the potential energy of the operating fluid to cause normal operation of the pump at all other times.

Other objects and advantages will appear from the following specification and the drawings, which are for the purpose of illustration only, and in which:

Fig. 1 is a vertical sectional view through the upper portion of my invention;

Fig. 2 is a vertical sectional view of an intermediate portion of the invention, carried downwardly from the lower end of Fig. 1;

Fig. 3 is a vertical sectional view of the lower portion of the invention, carried downwardly from the lower end of Fig. 2;

Fig'. 4 is a vertical sectional view of the motor and valve mechanism of my invention, showing the main valve member in its lower, or upstroke, position;

Fig. 5 is a vertical sectional view of the inlet end of the invention, showing the position of the parts when the pump piston strikes an accumulation of sand in the bottom of the pump cylinder;

Fig. 6 is a cross-sectional view taken on the line 6-6. of Fig. 1;

Fig. 7 is a cross-sectional view taken on the line 1-1 of Fig'. 1;

Fig. 8 is a cross-sectional view taken on the line 8-8 of Fig. 1;

Fig. 9 is a cross-sectional view taken on the line 9 9 of Fig. 1; and

Fig. 10 is a cross-sectional view taken on the line Ill- I0 of Fig. 1.

Referring to the drawings, Figs. 1, 2, and 3 show a fluid operated pump l0 having an upper tting Il by which the fluid operated pump is secured to the lower end of a conventional fluid supply tubing (not shown), by which operating fluid, such as oil, under relatively high pressure is delivered to the pump. The upper fitting I`I is provided with a longitudinal bore l2 having a counter-bore I3, the upper end of the counterbore being internally threaded to receive a tubular nut i4 which rigidly retains in the counter-bore the head l5 of a depending valve tube I3. An annular clearance I1 is provided between the valve tube I3 and the bore I2 of the iitting Il to permit axial alignment of the valve tube with valve mechanism to be described hereinafter. The tubular nut I4 is tightened against the shoulder in fltting ll with a slight axial clearance between the nut I4 and the head I3 so that the valve tube can float laterally.

The upper fitting l I is provided on its lower end with external threads i3 to which is threaded a tubular motor cylinder 20. As shown in Fig. 2, the lower end of the motor cylinder 20 is threaded to a tubular plug member 2l, the lower end of which is threaded by external threads to the upper end of a tubular pump cylinder 22. As shown in Fig. 3, the lower end of the tubular pump cylinder 22 is threaded to the upper end of an inlet member 23, the lower end of which is threaded to a tubular seating member 24 provided at its lower end with a conical seating face 23, which is adapted to seat in the conventional pump inlet shoe (not shown) carried by the lower end of a production tubing (not shown) which, as Awill be understood, extends upwardly around the fluid operated pump I0 to the surface of the ground so as to receive pumped well fluid Ifrom a discharge port 21 of the inlet member 23 to convey such discharged well fluid from the fluid operated pump to the surface of the ground, as is generally well known in the art.

The tubular seating member 24 has threaded to its upper end a. tubular collar 23 provided with an internal annular shoulder '23 adapted to clamp an annular `main valve seat member 30 against the upper end of the tubular seating member. The valve seat member 33 is provided with a semi-spherical valve seat 3l on which is adapted to seat by gravity an inlet ball valve element 32, the valve seat and the ball valve element constituting the main inlet valve of the invention. The upper end of the tubular collar 28 is provided with circumferentlally spaced fingers 33 providing spaces 34 therebetween to permit the flow of well fluid from the tubular seating member 2'4 into the inlet member 23 when the ball valve element 32 is raised olf its seat 3|. As will be noted, the lower endrof the inlet member 23 forms an inlet chamber 36, with which communicates a substantially vertical passage 31 leading upwardly through the inlet member to the upper end thereof to communicate with the interior of the pump cylinder 2'2.

The central portion of the inlet member 23 is provided with an axial bore 33 in which is disposed a slidable, tubular valve carrier 39 adapted to be retained normally in its uppermost position as shown in Fig. 3 by a compression spring 40 disposed therein. Communicating with the lower end of the axial bore 33 is a radial port 4I, which i permits fluid to 'freely enter and discharge from the lower end of the axial bore to permit 'reciprocation of the valve carrier 39 therein. The valve carrier 39 is provided with a semi-spherical upper face42 which carries a discharge ball valve inember 43 which is normally held in its seated position shown in Fig'. 3 by the compression spring 40 against an annular valve seat 44 retained in the inlet member 23 by a threaded tubular nut 45. The ball valve member 43 and its valve seat 44 constitute a discharge valve means of the inworksinadischargechamberllwhicheolm" municates withthe'exterior oitbeinlet 28 through the discharge'wrt 2 1.

Supportedontheupperendottheinletmemberllisatubularpumpcylinderlinerllhaving alowersectionllandanuppersectionllthe sections of the cylinder liner being clamped between the inlet member andthetubularplug member 2|. Disposedinthe cylinderliner 48 is a tubular pump piston member II whichisreciprocable in the cylinder liner and forms a huid-tight ilt with the upper section 5l thereof. Threaded-l lyconnectedtotheupperendofthepumppiston memberlI isavalvebody52.bestshowninlg.l. The valve body 52 is provided with external vthreads58towhichiathreadedtheupperend of a tubular motor piston Il, which extends downwardly in the tubular motor cylinder 28 and forms a fluid-tight sliding iit therewith, the motor cylinder providing an annular space 55a.

The valve body 52 has a minor bore 58 and a major bore 51 of greater internal diameter than the minor bore, the upper end of the valve body being provided with a tubular head 58 connected thereto by means of threads 59. The tubular head 58 is provided with an annular shoulder 8| which engages a shoulder 82 borne on a valve sleeve 63 which is press-iltted or otherwise secured in the upper end of the major bore 51. The valve sleeve 63 is slidably disposedl on the valve tube I6 in huid-tight engagement therewith and its bore is provided with an upper annular groove El, a central annular groove 65, and a lower annular groove 86. The annular shoulder 62 is of member smaller external diameter than the adjoining part of the tubular head 58 so as to provide an annular space 61 therebetween, which communicates through circumierentially spaced radial ports 68, as best shown in Fig. 6, with the annular groove 84. The valve tube I8 is provided in its external surface with a plurality of circumferentially spaced upper vertical grooves 10, which, in the position of the parts shown in Fig. 1, span the upper 'annular groove 54 and the central annular groove 65. The lower end of the valve tube IB is provided with a plurality of circumferentially spaced lower vertical grooves 1I,

the lower ends of which are open to the interior of the pump piston member 5l. Also communicating with the annular space 51 are a plurality of radial ports 12 formed in the tubular head 58. The central annular groove 85 communicates through radial ports 13 formed in the valve sleeve 63 with the exterior thereof, and the` lower annular groove 8B similarly communicates through radial ports 14 with the exterior of the valve sleeve.

Disposed in the space provided between the valve sleeve 63 and the valve body 52 isa main valve member 15 of substantially tubular form, having a major portion 19 making fluid-tight slidable engagement with the maior bore 51, and a minor portion 11 making iluid-tight slidable engagement with the minor bore 55. The exterior surfaces of the major and minor portions 16 and 11 are separated by an annular channel 19, and the lower exterior surface of the major portion 16 is provided with a plurality of circumferentially spaced vertical throttling grooves 88 of dierent lengths. With the main valve member 15 in the position shown in Fig. 1, the annular channel 19 spans an annular groove 8| formed in the major bore 51 and a plurality or circumferentially spaced radial ports 82 formed in the valve 6 K bodvgll.' Thendillportllt throughanannularpaoe88.bctweenthovalv` body," and the maint cylinder '2., with radial vexhaust ports 84 formed in the motor cylinder.

Theannul'ar groove 8i also is intersected by and; communicates with vertical 85 formed in the valve body.

Also formed in the main valve member 15 are radial ports 81 which communicate with an annular groove 88 formed on the exterior ofthe valve member and with an annular groove 89 formed ouv the interior of the valve member. Communicating with the inner-annular groove 89 is a lower helical groove 9| and an upper helical groove 9| which communicates at its upper end with an annular channel 92, which in turn communicates at its upper end with vertical passages 93 formed in the upper end of the valve member, and which communicate with the 'upper end thereof. Also formed in the central portion of the valve body 52 is a radial port 94. Communicating with the lower end of the vertical passages 85 are longitudinal grooves 95 formed in the lower threaded portion of the valve body 52, and which also communicate with the upper end of an annular space 96 provided between the lower end of the valve body and the upper end of the tubular motor .piston 55.

As best shown in Fig. 2, the lower end of the tubular pump piston 5| is provided with an auxiliary valve means |00, which also serves as a jetting means as described hereinafter. The auxiliary valve means |00 includes a plug member IOI threaded into the lower end of the tubular pump piston member 5I, provided with a tubular neck |02 extending upwardly into the pump piston member, the plug member being provided with a' conical valve seat |03 and having radial ports IM just above the valve seat in the tubular neck. Secured in the upper end of the tubular neck, as by a cross pin |05 is a. valve cage |06 having a ball check valve |01 therein. Extending into the plug member IOI is a valve assembly |09 having a central stem IIO, the stem being provided with upper radial ports II3 and lower radial ports III communicating with an axial passage IFI. Threaded on the lower end of the stem IIO is a nut I I5 which supports a washer IIB. Carried by the stem IIO is a lower sleeve I I1 which makes a sliding fit in the plug member I0 I. Ailso carried on the stem I I 0 above the sleeve |I1 is an upper-sleeve II8 which makes a sliding t in the tubular neck |02 and is provided at its lower end with a conical seating face I I9 which is adapted to seat on the conical valve seat |03 of the plug member I 0I, the upper-sleeve being when the valve assembly |09 is in the position shown in Fig. 2 an annular space is provided between the upper-sleeve II8 and the lower-sleeve II1, which communicates with the lower radial III. The valve sleeve II8 engages an enlarged head |I2 formed on the up'per end of the stem` The sleeve II1 engages the washer II6. The valve sleeve |I8 is provided with a conical seating face II9 which is adapted to seat on the valveseat I 03. The sleeve II1 is of such length that radial passages lll formed in the stem IIO and communicating with the axial passage III are open'when the head II2 is in contact with the valve sleeve II 8. Also formed on the exterior of the valve sleeve I8, above and communicating with the radial ports |04 is a helical groove |20 which also communicates with the interior of the upper end of the tubular neck |02.

During operation, operating fluid, such as, for

' thereto to cause the upstroke of the motor piston and the pump piston member 5I, as will be described more in detail hereinafter. On the upstroke of the pump piston member 5| the suction created thereby in the lower end of the pump cylinder liner 48 is communicated through vertical passages 31 to unseat the inlet ball valve element 32 and to draw well iiuid from the well through the tubular seating member 24, the inlet chamber 38, the vertical passage 31, and into the lower end of the pump cylinder liner 48. This is the intake, or suction, stroke of the pump piston member 5|. When the pump piston member is moved downwardly on its downstroke, as will be described hereinafter, the inlet ball valve element 32 seats on its valve seat 3|, to prevent well uid from passing from the inlet chamber 38 back into the well, and the increased pressure in the lower end of the pump cylinder liner 48 moves the discharge ball valve member 43 downwardly oi its seat on the end of the valve seat 44 to permit the well uid in the lower end of the pump cylinder liner 48 to be discharged through the discharge chamber 46 and the discharge port 21 into the production tubing (not shown) surrounding the uid operated pump, through which it is conveyed to the surface of the ground. Due to the relatively large cross-sectional area of the ports and passages in the inlet member 23, the iluid operated pump l is well adapted to pump extremely heavy En` viscous oil and oil containing large quantities of sand or other solid materials. As will be noted, the construction of the inlet member 23 permits the use of an inlet ball valve element 32 of a diameter which is a high percentage of the diameter of the iluid operated pump I0, and the discharge ball valve member 43 is also of relatively great diameter, which feature facilitates the pumping of heavy or viscous oils. As will also be understood, the discharge ball valve member 43 is normally retained closed on the upstroke of the pump piston member by suction in the lower end of the pump cylinder liner 48 and by the action of the compression spring 40. The radial port 4| communicating withv the rbottom of the valve carrier 39 merely provides a vent for the lower end of the carrier,

In operation, the high pressure operating uid is conveyed downwardly from the upper tting I I through the valve tube I6 and from the open lower end thereof-into the interior of the tubular pump piston member 5|, consequently exerting a relatively high force downwardly on the pump piston member, tending to move the pump piston member and the connected motor piston 55 downwardly. As will be understood, such high iiuid pressure within the pump piston member 5| normally maintains the auxiliary valve means |00 in its closed position as shown in Fig. 2 in which the seating face H9 of the valve sleeve lll is channel 92, and the vertical passages 93, to cause seated .in sealing relation on the conical valve seat |03, and in which the ball check valve |01 is maintained in its closed position on the seat of the'valve cage |06. Consequently, the high pressure operating uid is prevented during a normal downstroke of the pump piston 5| by the closure of the auxiliary valve means |00 from passing out of the lower end of the tubular pump piston.

With the parts in the positions illustrated in Figs. 1, 2, and 3, the fluid-operated pump is ready to commence the downstroke of the pump piston member 5|. In this position, the main valve member 15 is in its uppermost position. In this position, the lower end of the motor piston 55 and the space 55a therebelow in the motor cylinder 20 is in open communication with the relatively low iiuid pressure in the production tubing, through the annular space 95, the longitudinal grooves 95, the vertical passages 85, the annular groove 8|, the annular channel 19 on the minor portion 11 of the main valve member 15, the radial ports 82, the annual space 83, and the radial exhaust ports 84. Consequently, fluid in the space 55a may readily exhaust therefrom as the motor piston 55 travels downwardly. Downward travel of the motor piston 55 and the pump piston member 5I iscaused by the application of force by the high pressure operating fluid vexerted on the interior` of the lower end of the pump piston member 5|, as pointed out hereinabove. The weight of the piston assembly also assists in this downward movement. The downstroke of the pump piston member 5I is at relatively high velocity, due to the direct application of a large volume of operating fluid thereto.

During the downward movement of the motor and pump piston assembly, when the lower annular groove 66 of the valve sleeve 63 registers with the upper end of the lower vertical grooves 'Hl operating fluid under high pressure is conveyed thereto through the grooves, and passes outwardly through the radial ports 14 and into and upwardly through the annular channel 92 and the vertical passages 93 to the upper end of the main valve member 15.

The main valve member 15 is of the differential area governing type, generally similar in construction and operation to that shown in my Patent No. 2,311,157, to which reference is hereby made for the details thereof. The major difference is that the main valve member of said Patent No. 2,311,157 is a four-way valve adapted to connect the two ends of a motor piston alternatively with high and low pressures, whereas my present pump is preferably of the single acting type in which the only action of the main valve the radial ports 81, the annular groove 88, and the radial port 94. As the piston assembly approaches the end of its downstroke, the lower annular groove 58 of the valve sleeve 63 registers with the lower vertical grooves 1| of the valve tube I6, which permits high pressure operating fluid to ilow to the upper end of the main valve member 15 through the vertical grooves 1|, the lower annular .channel 66, the radial ports 14, the annular annular space 55 tothe lower end of the motor n piston 55.

During the upstroke of the motor piston 55, as soon as the radial ports 13 and 14 pass out of registry with the lower vertical grooves 1| in the valve tube I5, high-pressure operating fluid can no longer pass directly therethrough into the space above the main valve member 15 to retain it in its lower position illustrated in Fig. 4. However, high-pressure operating duid can still pass to the upper end of the main valve member 15 through the upper helical groove 9 l so as to maintain the main valve member inv its lowermost position during the upstroke.

As the motor piston 55 approaches the end of its upstroke, the central annular groove 55 of the valve sleeve 53 registers with the upper vertical grooves 15 to place the space above the main valve member 15 in communication with low iluid pressure in the annular space I3 through the radial ports 15, the upper vertical grooves 10, the upper annular groove 54, the radial ports 50, the annular space 01, and the radial ports 12, permitting the operating iluid bearing on the lower end of the main valve member 15 to move the same upwardly to the position shown in Fig. 1, in which the duid-operated pump Il is ready to perform its downstroke. It the motor piston 55 on its upstroke carries upwardly beyond the position shown in Fig. 1 so as to close or partially close the radial exhaust ports 54, iluid above the piston cannot exhaust through the exhaust ports, and this serves as a dash-pot to bringthe motor piston to a stop on its upstroke.

The huid-operated pump I0 is preferably designed so that the valve member assembly |09 connected to the lower end of the pump piston member 5| moves down into the inlet member 23 to a lowermost point adiacent the discharge ball valve element 43 on the downstroke of the strikes the upper end of the lower sleeve I1, stopping further downward movement of the upper sleeve. Continued downward movement of the pump piston member 5| moves the conical valve seat |05 away from the seating face Il! on the lower end of the upper sleeve III, permitting access oi the high pressure operating fluid from the ports |04 to the seating face IIS.v Since the iluid pressure in the upper end oi' the neck |02 is relatively low, an upwardly directed pressure differential is thus impressedjon the upper sleeve H8, causing it toinove upwardly away from the upper end of the lower sleeve i|1, thus opening iluid communication between the ports |04` and the axial bore through the lower radial ports ill, which permits operating iluid under high pressure to flow therethrough and downwardly through the axial passage from the lower end of which it is jetted into the accumulated mass of sand or other solid foreign material. The jetting action of such operating uid discharged from the lower end of the axial passage tends to stir up and loosen the mass of sand therebelow so 'that it can be conveyed out of the inlet member through the discharge valve means by continued downward movement of the pump piston. The pump piston member 5| will, of lcourse, continue its downward travel, durin g which time any excess iluid pressure in the upper portion of the neck |02 will lift the ball |01 oi its seat to relieve the` same, and such travel will continue until the bottom-of the plug |0| strikes the washer ||5 and is held from further downward travel (as shown in Fig. 5) or until it finishes its normal downstroke or until the permeability of the sand therebelow is so low, or becomes so low, that the fluid pressure below the pump piston member rises substantially. If, of course, the pump piston member 5I is prevented by sand therebelow from ilnishing its downstroke, continued jetting may in time clear the discharge i valve means to permit the pump piston member pump piston, the lower end of the valve member assembly |09 approaching the dotted line'A-A in Fig. 3 in its normal stroke. In the event that sand or other solid matter accumulates in the upper end of the inlet member 23, as indicated by the numeral |2| of Fig. 5, so that the bottom of the .valve member assembly |09 strikes this accumulation of solid matter on the downstroke of the pump `piston 5|, the valve member assembly will stop its downstroke. The pump piston member 5| will continue to move downwardly', and the upper sleeve ||8 will move with it, remaining seated on the conical valve seat |03, until the uper sleeve has moved downwardly away from the head ||2 suillciently to open the upper radial ports H3. As soon as the upper radial ports ||3 open slightly, the interior of the neck Y |02 above the sleeve ||8 is open to relatively low discharge pressure through the radial parts ||3 and the bore and the iluid pressure in the neck drops to such discharge pressure. The upper to complete its downstroke, which is a common condition of operation. The pump piston member 5| will thus hang up until either the discharge valve means is cleared of sand sumciently to permit the pump piston to complete its normal downstroke or until the iluid pressure on the lower end of the pump piston risesto a value at which it overbalances the downward pressure of the operating iluid exerted on the interior thereof. If the permeability of the sand pack below the pump piston member 5| is sumciently low, the fluid preslsure will rise to such overbalancing value, either before or after the plug 0| strikes the washer I5. As soon as this condition is reached the fluid pressure of the operating fluid will be applied to ,the entire cross-sectional area of the bottom of the pump piston member '5|, and, since this area is substantially greater than the eiective area causing its downward movement, the pump piston will reverse its stroke and move upwardly. The valve member assembly |09 will, of course, start to move upwardly with the pump piston member 5|, but, due to relatively high iluid pressure in the upper end of the neck |02 which tends to move the valve member assembly downwardly relative to the piston member, thevalve memberA assembly will also start to move downwardly relative to the pump piston member. Such relative movement of the pump piston member 5| and the valve member assembly |09 continues until the upper sleeve I8 again seats on the conical valve seat |03 to close the radial ports III,

ll upon which occurrence the ilow of high pressure operating iluid 'through the ports' Ill is stopped and jetting action also stops. The head I I2 also seats on the upper end of the upper sleeve II8 to close the upper radial ports H3, and the ports are again in the position shown in Fig. 2 in which the auxiliary valve means is fully closed. Due to the relatively small cross-sectional area of the helical groove |20, the rate of downward movement of the valve member assembly |09 rela-v tive to the pump piston member I, from the position shown in Fig. 5 to the position shown in Fig. 2, is relatively slow, and by the time that the valve member assembly has resumed its closed position shown in Fig. 2 its lower end will be a substantial distance above the sand pack therebelow. When, however, the valve member as- -sembly |09 returns toits seated position illustrated in Fig. 2, the ow of operating iluid therethrough to the axial passage III is cut oil, and the piston member 5I reverses its stroke and moves downwardly again under the pressure exerted by the operating fluid on the interior thereof. Such renewed downward movement of the pump piston member 5| continues until the valve member assembly Il! again strikes the accumulation of solid materials in the inlet member 23 at which time the jetting action of oper-` ating iiuid from the axial passage I I I is resumed, and, if the inlet member is still plugged, the piston member 5l again reverses its stroke and moves upwardly. Thus, the pump piston member 5I, in such case, reciprocates in short strokes, drilling into and out of the accumulation of sand I2I until the sand is loosened and carried from the inlet member by the downward pumping action of the pump piston. Of course, as soon as the va1ve member assembly I 09 can move downwardly to the end of its normal vdownstroke, indicated by the line A-A of Fig. 3, a normal upstroke of the pump piston member 5I then occurs and normal pumping is resumed. While the pump piston member 5I is reciprocating in short strokes to attempt to remove the accumulation of sand from the inlet member 23, obviously, the volume of oil pumped from the well will drop materially, and the bottom hole condition can and will be apparent to the operator on the surface. As soon as inlet member 23 is free from accumulated sand, the normal pumping stroke of the pump piston member 5| will be resumed to provide normal pumping capacity, indicating to the operator that the temporary plugged condition has been remedied. If, however, the pump production falls below the normal rated capacity of the pump and remains at a reduced ligure over an. extended period of time it may be necessary to pull the pump to permit cleaning oi.' the inlet member 23. However, under ypractically all normal operating conditions the pump i0 will clear` itself of such accumulation of sand and other solid materials during operation as described. It is also to be noted that due to the fast, high velocity downstroke of the pump piston member 5I considerable turbulence is caused `in the pump inlet member, tending to-maintain any sand or other solid material therein in suspension in the oil therein, thus additionally helping to prevent the accumulation and packing thereof in the inlet member.

The velocity of the upstroke of the piston assembly is relatively slow, compared to the velocity of the downstroke, due to the fact that the area of the motor piston 55 is large compared with the area of the interior of the valve tube I6. The relative upward and downward velocities of the piston assembly will be inversely as such areas without considering the compressibility cf the operating fluid. Actually, however, in a deep well installation the-operating uid is substantially compressed, and on the downstroke of the piston assembly its velocity may be higher in actual operation than the above relation would indicate, as the only load on the piston assembly during its downstroke is the mechanical and hydraulic friction, and the operating uid can expand and impart a greater velocity to the piston assembly. I prefer to design the parts of the fluid operated pump I0 so that the upstroke of the piston assembly occupies between 75% and 90% of the total cycle time, the balance being occupied by the downstroke of the pump piston member. As pointed out above., this .has the added advantage of preventing the gas from flashing out of the oil being pumped.

Although I have illustrated and described a preferred embodiment of the invention, it is to be understood that various changes may be incorporated therein without departing from the spirit of the invention, and, consequently, l do not desire to be limited to the specic form shown, but desire to be afforded the full scope'of the following claims.

I claim as my invention:

l1. In a fluid-operated deep well pump, the combination of: a pump cylinder; a pump piston in said cylinder; inlet and discharge valve means connected to one end of said cylinder; a source of high-pressure operating iiuid; means for utilizing said operating iiuid Lto move said piston axially in said cylinder so as to pump well fluid from said one end of said cylinder through said valve means; auxiliary valve means carried by said piston; and passage means communicating between said pressure source and said auxiliary valve means, said auxiliary valve means being adapted to provide iluid communication between said passage means and said one end of said cyl- 4 inder, said auxiliary valve means .being normally maintained in closed position but adapted to be opened in response to said piston striking solid foreign matter in said end of said cylinder to admit operating fluid thereto from said passage means.

2. In a fluid-operated deep well pump, the combination of: cylinder means; a motor piston in said cylinder means; a pump piston in said cylinder means; means connecting said pistons to- 5 gether for unitary movement; a source of highpressure operating uid; means for supplying said operating fluid to said pistons so as to reciprocate the same in said cylinder means; va1ve means carried by said pump piston; and passage means 0 communicating between said source and said valve, means, said valve means being operable in response to striking solid foreign material in one end of said cylinder means to admit Voperating fluid from said pasage means to said end of said cylinder means.

3. In a duid-operated deep well pump, the combination of: a pump cylindei` having apump piston therein; fluid pressure means for reciproeating said pump piston in said cylinder to pump 0 well fluid from a well, said means being adapted to be actuated by the supply of an operating fluid thereto under relatively high pressure; jetting means carried by said piston; and means for admitting said operating uid to said jetting means in response to said pistonstrikingsolid foreign material in said cylinder, so as to direct a jet of said operating iiuid against said. foreign material.

4. In a well pump, the combination ofz' a pump cylinder; a pump piston in said cylinder; `inlet and discharge valves for one end of said cylinder; fluid pressure means for reciprocating said pistonin said cylinder so as to pump well fluid from said one end thereof; and valve means carried by said piston and operable to open in response to striking solid foreign material in said one end of said cylinder to convey fluid under pressure into said one end of said cylinder said valve means communicating with said iiuid through passage means 5. In a huid-operated pump, the combination of cylinder means; a stationary tubular mempleSSule means f ber extending into said cylinder means, one end of said tubular member being adapted to Acornmunicate with a. source of high-pressure operating iluid; and a piston assembly reciprocable in said cylinder means on said tubular member, saidv piston assembly includinga tubular motor piston, a tubular pump piston the interior of which is ofl smaller eiective area than the veil'ective area of said motor piston and atall times in open communication with the interior of said tubular member, and tubular valve means adapted to cooperate with said tubular member to intermittently convey operating fluid from said tubular member to one end of saidmotor piston to move said piston assembly axially in said cylinder means in one direction, the action of said operating uid on said interior of said pump piston alternately moving said piston assembly in the opposite direction. y

6. In a fluid-operated pump, the combination of r a source of operating fluid under relatively high pressure; a motor cylinder having a motor piston therein; a pump cylinder having a pump piston therein, the interior of said pump piston having an effective area substantially less than the eie'ctive area of one end of said motor piston and in fluid communication with said source so that said operating fluid tends to move said 'pump piston axially in one direction; means for` operatively connecting said pistons together; and means for intermittently admitting said operating fluid to said end of said motor pistonso as to move said motor piston axially in the opposite direction.

7. In a fluid-operated pump, the combination of a source of operating fluid under relatively high pressure; a motor cylinder having a motor piston therein; a pump cylinder having a pump piston therein, the interior of said pump pistonhaving an -elective area substantially less than the effective area of one end of said motor piston and in iiuid communication with said source so that said operating fluid tends to move said pump piston axially in one direction at a relatively high velocity; means for operatively connecting said pistons together; and means for intermittently admitting said operating fluid to said end of said motor piston so as to move said motor piston axially in the opposite' direction at a relatively low velocity.

8. In a fluid-operated pump, the combination of cylinder means; a motor piston in said cylinder means; a pump piston in said cylinder means; meansoperatively connecting said pistons together into a unitary piston assembly; and means for supplying high pressure operating fluid to said piston assembly so as to move it at rela- 14 tively high velocity in one direction and` at relatively low velocity in the opposite direction, both directions of movementof said piston assembly being positively impelled by said operating fluid. 9. In a fluid-operated pump. the combination 'of cylinder means; a piston assembly in said cylthrough said discharge valve means; and means for supplying high-pressure operating iluid to said piston assembly so that it. moves axially in said one direction at relatively low velocity and so that it moves axially inY said other direction at relatively high velocity, both directions of movement of said piston assembly being positively impelled by said operating fluid.

10. In a duid-operated pump, the combination of cylinder means; a reciprocable piston assembly in said cylinder means, including a motor piston and a pump piston; inlet and discharge valve means connected to said cylinder means; a tubular member extending into said cylinder means and into said piston assembly and adapted to convey a high pressure operating iluid to said piston assembly so as to reciprocate the same relative to said tubular member; supporting means for supporting said tubular member relative to said cylinder means so that said tubular member may be initially moved laterally to an adjusted position relative to said cylinder means so as to axially align said tubular member with said piston assembly; and means for securing said tubular member in fluid-tight engagement with said supporting means in Isaid adjusted position. 11. In a uid operated deep well pump, the combination of a pump cylinder having a pump piston therein; valve means communicating between a source of fluid under high pressure and one end of said pump cylinder; a pump inlet and a pump discharge communicating with said end oi said cylinder; and means for opening said valve means in response to at least a predetermined accumulation of solid foreign material in said end of said pump cylinder, so as to admit a jet of said fluid into said end of said cylinder and directed towards said pump discharge.

12. In a fluid operated deep well pump, the combination of z a pump cylinder having a pump piston therein; valve means communicating be-L tween a source of fluid under high pressure and one end of saidA pump cylinder; and means for opening said valve means in response to at least a predetermined accumulation of solid foreign rst area and in communication withsaid end operated deep well pump, the

of said cylinder means; means for admitting high pressure operating uid to said first area so as to exert a force against said first area tending to move said piston means axially in one direction in said cylinder; and auxiliary valve means for admitting high pressure operating iiuid to said end of said cylinder means so as to exert a force against said second force area tending to move said piston means axially in the opposite direction.

x 14. In a fluid operated deep well pump, the combination of: cylinder means; inlet and discharge valve means communicating with one end of said cylinder means; piston vmeans in said cylinder means, said piston means having a first effective force area and a second eifective force area, said second area being greater than said first area. and in communication with said end of said cylinder means; means for admitting highv pressure operating fluid to said first area so as to exert a force against said iirst area tending to move said piston means axially in one direction in said cylinder; auxiliary valve means for admitting high pressure operating fluid to said end of said-cylinder means so as to exert a force against said secondforce area tending to move said piston means axially in the opposite direction; and means for opening said auxiliary valve means in response to a predetermined accumulation of solid foreign material in said end ofsaid pump cylinder.

15. In a fiuid operated deep well pump, the combination of: cylinder means; inlet nd discharge valve means communicating with one end of said cylinder means; piston means in said cylinder means, said piston means having a iirst` effective force area and a second effective force area, said second area being greater than said first area and in communication with said end of said cylinder means; means for admitting high pressure operating fiuid to said first area so as to exert a force against said first area tending to move said piston means axially in one direction in said cylinder; auxiliary valve means for admitting high pressure operating fluid to said end of said cylinder means so as to exert a force against said second force area tending to move said piston means axially in the opposite direction; means for opening said auxiliary valve means in response to a predetermined accumulation of solid foreign material in said end of said pump cylinder; and means for closing said auxiliary valve means after said piston means has moved in said opposite direction a distance less than the normal stroke of said piston in said op posite direction.

16. In a fluid operated deep well pump, the combination of: cylinder means; piston means in said cylinder means, said piston means including a motor piston having a first effective force area, and a pump piston member having a second in said cylinder means, said piston means including a motor piston having a rst eiiective force ond eifective'force area, said first force area being greater than said second force area, said secv ond force area-being adapted to be in open communication withfa source of high pressure operating fluid capable ofexerting a force thereon to move said piston means axially in one direction; and valve means adapted to provide intermittent communication between said source and said rst force area so as to move said piston means axially in the opposite direction, said force areas being so related that said piston means moves in said one direction at a relatively high speed and moves in said opposite direction at a relatively low speed.

18. In a iiuld operating deep'well pump, the combination of: cylinder means; inlet and discharge valve means connected to one end of said cylinder means; piston means in said cylinder means, said piston means including a motor piston having a first effective force area, and a pump piston in said one end of said cylinder vmeans and having a. second effective force area,

. of exerting a force thereon to move said piston means axially toward said one end of said cylinder means to perform the return stroke thereof; and valve means adapted to provide intermittent communication between said source and said first force area so as to move said piston axially in the opposite direction to perform the working stroke thereof, said areas being so related that said piston means moves on said return stroke at relatively high velocity and moves on said working stroke at relatively low velocity.

19. In a uid operated deep Well pump, the combination of: cylinder means; inlet and discharge valve m'eans connected to one end of said cylinder means; piston meansin said cylinder means, said piston means including a motor piston having a first effective force area, and a pump 'combination of: cylinder means; piston means having a second effective force area, said first force area being greater than said second force area, said second force area being adapted to be in open communication with a source of high pressure operating uid capable of exerting a force thereon to move said piston means axially 'toward said one' end of said cylinder means to perform the return stroke thereof; and valve means adapted to provide intermittent communication between said .source and said first force area so as to move said piston axially in the opposite direction to perform the working stroke thereof, said areas being so related that said working stroke utilizes over of the total time of the pumping cycle.

20. In a fluid-operated deep well pump, the combination of; cylinder means; piston means extending into said cylinder means and reciprocable relative thereto, said piston means having a first relatively large effective force area and a second relatively smaller effective force area, said force areas facing oppositely, said smaller force area being incontinuous open communication with a source of high-pressure operating fluid during operation of the pump, said piston means being provided with a valve cylinder; and valve means in said'valve cylinder adapted in operation of the pump to provide communication between said larger force area and said source and alternately between said larger force area andv a lower-pressure fiuidbody, the force Y v exerted by said high-pressure fluid on said smaller force area moving said piston means in one dlrection when said larger force area is in communication with said body, and the force exerted by said high-pressure-fluid on said larger force area moving said piston means in the opposite direction when said larger force area is in communication with said source.

21. In a fluid-operated deep well pump, the combination of cylinder means; piston means extending into said cylinder means and reciprocable relative thereto, said piston means having a first relatively large eiective force area and a second relatively smaller eiective force area, said force areas facing oppositely, said smaller force area being in continuous open communication with a source of high-pressure operating fluid during operation of the pump, said piston means being provided with a valve cylinder; differential area m'ain tubular valve means in said valve cylinder adapted in operation of the pump to provide communication between said larger force area and said source and alternately between said larger force area and a lower pressure fluid body, the force exerted by said high-pressure iluid on said smaller force area moving said piston means in one direction when said larger force area is in communication with said body, and the force exerted by said high-pressure fluid on said larger force area moving said piston means in the opposite direction when said larger force area is in communication with said source, said main valve means having a relatively small valve area continuously in communication with said source and having a relatively large valve area adapted to be alternately placed in communication with said source and said body; and pilot valve means extending into said valve means and controlling the operation of said main valve means, said pilot valve means being adapted to open communication between said large valve area and, alternately, said source and said body.

22. In a fluid-operated deep well pump, the combination of: cylinder means providing an engine cylinder and a pump cylinder in axial alignment; piston means in said cylinder means providing an engine piston extending into said engine cylinder and a pump piston extending into said pump cylinder, said engine and pump pistons being connected together, said piston means having a large effective force area and a smaller effective force area, said large force area being greater than said small force area, said small force area being adapted to be in continuous open com'- munication with a source of high-pressure operating fluid, the eiect of which on said small force area continuously tends to move said piston means axially in one direction during operation of the pump; means for admitting a uid to be pumped to said pump cylinder means; main valve means carried by said piston means and adapted to provide communication between said larger force area and, alternately, said source of high-pressure operating iluid and a source of lower-pressure fluid, said main valve means being tubular in form and movable relative to said piston means to provide such communication; and pilot valve means extending into said main valve means and alignment; piston means in said cylinder means 18 providing an engine piston extending into said engine cylinder and a pump piston extending into said pump cylinder, said pistons being connected together, said piston means having a relatively small unbalanced area and a relatively large balanced area; means for constantly applying a iluid pressure differential to said small unbalanced area tending to move said piston means inl one direction; master valve means carried by said piston means and adapted to be moved to apply a, fluid pressure differential to said large balanced area tending to cause said piston means to move in the opposite direction; and pilot valve means extending into said piston means and operable in response to movement of said piston means to control the operation of said master valve means.

24. In a fluid-operated deep well pump, the combination of: cylinder means providing an engine cylinder and a pump cylinder in axial alignment; piston means in said cylinder means providing an engine piston extending into said engine cylinder and a pump piston extending into said pump cylinder, said pistons being connected together, said piston means having a relatively small unbalanced area and a relatively large balanced area, said piston means having a valve chamber therein; means for constantly applying a fluid pressure differential to said small unbalanced area tending to move said piston means in one direction; master valve means carried by said piston means in said valve chamber and slidable in substantially fluid-tight relationship therein and adapted to be moved to apply a fluid pressure differential to said large balanced area tending to cause said piston means to move in the opposite direction, said master valve means having a major diameter on one end thereof and a smaller minor diameter on the other end thereof, said minor diameter being constantly exposed to high-pressure fluid during operation of the pump tending to move said master valve means in one direction; and pilot valve means extending into said piston means and operable in response to movement of said piston means to alternately expose said major diameter to high pressure and relatively low pressure to cause reciprocation of said master valve means. y

25. In a fluid-operated deep well pump, the combination of: a double-acting engine including engine piston means having a large area and a relatively small area, said areas being faced in opposite directions, said large area being adapted to have applied thereto pressure differential to move said engine 'piston means on its power stroke, said small area being adapted to have applied thereto a pressure diierential to move said engine piston means on its return stroke; master valve means carried by said engine piston means for controlling the application of pressure differentials to said engine piston means; pilot valve means in said engine piston means and operable when said engine piston means approaches the respective ends of its strokes to control the movement of said master valve means; and a singleacting pump connected to said. engine piston means and operable in response to reciprocation of said engine piston means to pump fluid from a well.

26. In a duid-operated well pump adapted to connected to a column of high-pressure uid and a column of discharge iluid at lower pressure, the combination of cylinder means; piston means extending into said cylinder means and reciprocable relative thereto, said piston means having opposed areas, one of said areas being in open communication with one of said columns at all times during operation oi' the pump; valve means carried by said piston means and movable to open uid communication between the other said area of said piston means and said columns alternately during operation of the pump, the :luid pressures on said areas being balanced in one position of said valve means; and piston extension means having a pressure diierential applied thereto when said valve means is in said one position. CLARENCE J. COBERLY.

REFERENCES CITED The following references are of record in the ille oi this patent:

Number UNITED STATES PATENTS Name Date Palm Nov. 20, 1923 Todd June 23, 1925 Gage et al. July 7, 1925 Scott Nov. 15, 1932 Robertson Feb. 13, 1940 Chenault Feb. 20, 1940 Coberly Aug. 4, 1942 Pankratz Sept. 14, 1943 Coberly Jan. 30, 1945 

